Electron irradiation of zein protein-loaded nano CaO2/CD for enhancing infectious diabetic wounds with adaptive hydrophobicity-to-hydrophilicity

Chronic diabetic cutaneous wounds resulting from inflammatory conditions present an ongoing challenge for current therapies and impose a significant burden on individuals with diabetes, impacting their quality of life. Infection-related diabetic skin wounds require dry conditions to inhibit bacterial growth. However, as the wounds progress, moisture becomes necessary to facilitate the healing process. In this study, we propose a novel therapeutic strategy for diabetic skin repair by creating bio-dressings with adjustable "hydrophobic" and "hy-drophilic" characteristics to accommodate the changing stages of the disease. We developed a skin dressing by loading calcium peroxide (CaO2) nanoparticles onto carbon dots (CD)-modified irradiated zein (Ir-Zein). This dressing releases reactive oxygen species (ROS) from CaO2, providing antibacterial effects, while the presence of CD enables a sustained release of CaO2. The calcium ions produced by CaO2 degradation further promote skin regeneration. Ir-Zein protein, a cost-effective and easily processed natural plant protein, exhibits excellent biocompatibility. Importantly, in diabetic rats with full-thickness skin defects, the CaO2/CD@Ir-Zein film significantly accelerated the healing of chronic wounds. Mechanistic investigations revealed that the film effectively reduced inflammation by inhibiting the polarization of macrophages towards the M1 phenotype and capturing pro-inflammatory cytokines. In summary, our findings demonstrate the effectiveness of the CaO2/ CD@Ir-Zein film's "adaptive hydrophobicity-to-hydrophilicity" in promoting the transition of chronic wounds from the inflammatory stage and skin repair. CaO2/CD@Ir Zein is a novel bio-dressing that can adapt to the changing environment of infected diabetic skin wound healing.